CN110317551A

CN110317551A - Adhesive tape

Info

Publication number: CN110317551A
Application number: CN201910247405.8A
Authority: CN
Inventors: 菱沼庆人; 高须健一郎; 宫崎健次
Original assignee: Sekisui Chemical Co Ltd
Current assignee: Sekisui Chemical Co Ltd
Priority date: 2018-03-30
Filing date: 2019-03-29
Publication date: 2019-10-11
Anticipated expiration: 2039-03-29
Also published as: JP7020984B2; JP2019178293A; CN110317551B

Abstract

The subject of the invention is to provide the adhesive tapes that waterproofness is excellent.Solution is, adhesive tape of the invention is the adhesive tape of the adhesive phase for at least one side for having independent air bubble foamed sheet and only bubble foamed sheet being arranged in, the arithmetic average roughness Ra of at least one side of above-mentioned independent air bubble foamed sheet is 1~12 μm, the peel strength of above-mentioned adhesive phase is 1.1N/25mm or more, with a thickness of 10 μm or more.

Description

Adhesive tape

Technical field

The present invention relates to the adhesive tapes for having independent air bubble foamed sheet and adhesive phase.

Background technique

In the past, foamed sheet due to such as resiliency, thermal insulation, waterproofness and moisture resistance it is excellent, be used in article Bale packing material will carry out the sealing material for protecting the peripheral part of component for influencing it by gas or liquid etc. to seal, incite somebody to action The various uses such as vibration and the fender of damping of shocks, the substrate of bonding sheet.It is public in patent document 1 as specific foamed sheet Opened so that the foamable polyolefin series resin sheet comprising thermal decomposable foaming agent is foamed and be crosslinked and the cross-linked polyolefin that obtains Based resin foamed (referring to patent document 1).

Existing technical literature

Patent document

Patent document 1: International Publication No. 2005/007731

Summary of the invention

Problems to be solved by the invention

But in recent years, in the small communication devices such as smart phone, wearable terminal, it is desirable that high waterproof performance.Cause This, from the viewpoint of waterproofness raising, the opening portions periphery such as gap, sim card slot for being generated between display panel and shell Configured with liner material.Liner material needs may adapt to the flexibility of the degree of the small difference of height on adherend surface, also, needs It is used to be temporarily fixed to the adhesiveness of allocation position.As the material for meeting such physical property, it is known that have foaming body and set Set the adhesive tape in the adhesive phase of at least one side of the foaming body.However, requiring higher waterproof performance in recent years, it is desirable that into The raising of the waterproofness of one step.

The present invention is proposed in view of problem above, and project is to provide the adhesive tape for showing good waterproofness.

The method used for solving the problem

The inventors of the present invention have made intensive studies, as a result, it has been found that, by for have independent air bubble foamed sheet and be arranged at this The adhesive tape of the adhesive phase of at least one side of independent air bubble foamed sheet, and make the peel strength of adhesive phase and with a thickness of certain More than, and make arithmetic average roughness Ra a certain range of independent air bubble foamed sheet, so that the waterproofness of adhesive tape improves, Complete the present invention.That is, the present invention is as described below.

[1] a kind of adhesive tape has independent air bubble foamed sheet and the adhesive of at least one side of the foamed sheet is arranged in The arithmetic average roughness Ra of layer, at least one side of above-mentioned foamed sheet is 1~12 μm, and the peel strength of above-mentioned adhesive phase is 1.1N/25mm or more, with a thickness of 10 μm or more.

[2] adhesive tape according to above-mentioned [1] is only provided with adhesive phase, above-mentioned hair in above-mentioned foamed sheet on one side The arithmetic average roughness Ra for steeping the another side of piece is 1~12 μm.

[3] adhesive tape according to above-mentioned [1] or [2], 50% compressive strength of above-mentioned foamed sheet are 40~300kPa.

[4] adhesive tape according to any one of above-mentioned [1]~[3], the interlaminar strength of above-mentioned foamed sheet is 0.8~ 3.0MPa。

[5] adhesive tape according to any one of above-mentioned [1]~[4], above-mentioned foamed sheet with a thickness of 0.1~1.5mm.

[6] adhesive tape according to any one of above-mentioned [1]~[5], the expansion ratio of above-mentioned foamed sheet is 1.2~ 20cm³/g。

[7] adhesive tape according to any one of above-mentioned [1]~[6], the mean air bubble diameter of above-mentioned foamed sheet are 20 ~150 μm.

[8] adhesive tape according to any one of above-mentioned [1]~[7], the degree of cross linking of above-mentioned foamed sheet are 25 mass % More than.

[9] adhesive tape according to any one of above-mentioned [1]~[8], above-mentioned foamed sheet contain polyolefin-based resins.

[10] adhesive tape according to any one of above-mentioned [1]~[9], above-mentioned foamed sheet contain 50 matter of polyvinyl resin Measure % or more.

[11] adhesive tape according to any one of above-mentioned [1]~[10], above-mentioned adhesive phase with a thickness of 10 μm with It is upper and 55 μm or less.

The effect of invention

According to the present invention it is possible to provide the adhesive tape for showing good waterproofness.

Detailed description of the invention

Fig. 1 is the schematic diagram of the experimental rig for evaluating interlaminar strength in embodiment and comparative example.

Specific embodiment

Hereinafter, being explained in detail to the present invention.

[adhesive tape]

Adhesive tape of the invention is the adhesive for at least one side for having independent air bubble foamed sheet and the foamed sheet being arranged in The adhesive tape of layer, the arithmetic average roughness Ra of at least one side of above-mentioned foamed sheet are 1.0~12 μm, the stripping of above-mentioned adhesive phase It is 1.1N/25mm or more from intensity, with a thickness of 10 μm or more.By meeting such important document, it is good waterproofness can be obtained Adhesive tape.

(independent air bubble foamed sheet)

< arithmetic average roughness >

Adhesive tape of the invention has the independent air bubble foamed sheet that the arithmetic average roughness Ra of at least one side is 1~12 μm (hereinafter also referred to as foamed sheet).If the arithmetic average roughness Ra of at least one side of foamed sheet is more than 12 μm, adhesive tape Waterproofness reduce.In addition, the arithmetic average roughness Ra in the face of foamed sheet is usually 1 μm or more.

From the viewpoint of improving the waterproofness of adhesive tape more, the arithmetic average roughness of at least one side of foamed sheet Ra is preferably 1.0~8 μm, more preferably 1.1~4 μm, further preferably 1.2~2 μm.

In the present invention, as long as the arithmetic average roughness Ra of at least one side of foamed sheet is above range, but It can be with the arithmetic average roughness on two sides all for above range.Wherein, it is only preferably provided with adhesive on one side in foamed sheet Layer, the adhesive tape that the arithmetic average roughness Ra of another side is 1~12 μm.The adhesive tape is due to being only arranged adhesive in one side Layer, therefore it is easy to manufacture, and operability when pasting to adherend is excellent.It only will be provided with bonding on one side in foamed sheet In the case that the adhesive tape of oxidant layer is inserted between component, the face for the foamed sheet that arithmetic average roughness Ra is 1~12 μm and conduct The component of adherend directly contacts.In this case, since the Ra of foamed sheet is small, the face of foamed sheet and the adaptation of component Become good, waterproofness improves.Further, due to also having and inserting for only in the adhesive tape for having adhesive phase on one side Enter to after between component, it is easily removable the advantage that.

The arithmetic average roughness Ra on the surface of foamed sheet can be straight by adjusting the degree of cross linking, the average bubble of foamed sheet Diameter, expansion ratio etc. are adjusted.

In addition, arithmetic average roughness Ra can be measured by method documented by embodiment.

50% compressive strength > of <

50% compressive strength of foamed sheet used in the present invention is not particularly limited, preferably 40~300kPa.Have The flexibility of the bonding sheet of foamed sheet with such 50% compressive strength is high, even if in the table for the adherend for pasting bonding sheet Face has small difference of height, is also adapted to the difference of height, waterproofness can be improved.In addition, having with such 50% The counter-force of the thickness direction of the bonding sheet of the foamed sheet of compressive strength is lower, and can simply be matched in narrow gap with compression state It sets.From the viewpoint of above like that, 50% compressive strength of foamed sheet is preferably 70~250kPa, more preferably 80~ 230kPa, further preferably 100~200kPa.

In addition, 50% compressive strength can be measured according to JIS K6767.

< interlaminar strength >

The interlaminar strength of foamed sheet used in the present invention is not particularly limited, preferably 0.8~3.0MPa.In this explanation So-called interlaminar strength in book is the value for indicating the tensile strength of thickness direction.

If the interlaminar strength of foamed sheet be 3.0MPa hereinafter, if adhesive tape flexibility it is high, waterproofness becomes good.Separately On the one hand, if the interlaminar strength of foamed sheet is 0.8MPa or more, the recycling property (rework) of adhesive tape becomes good.

Adhesive tape after being pasted on adherend, is temporarily removed sometimes in order to which position is micro-adjusted, then is pasted, At this point, the rupture etc. of adhesive tape occurs sometimes.So-called recycling property, expression have with operability when such remove-paste again The index of pass, the good adhesive tape of so-called recycling property refer to the few adhesive tape of the frequency ruptured when removing.

From the viewpoint of the adhesive tape of balancing good for obtaining waterproofness and recycling property, the interlaminar strength of foamed sheet is excellent It is selected as 0.9~2.5MPa, more preferably 1.0~2.0MPa, further preferably 1.2~1.8MPa.

Interlaminar strength can be adjusted by constituting type, mean air bubble diameter of resin of foamed sheet etc..In addition, at this Interlaminar strength can be measured by method documented by aftermentioned embodiment in specification.

< mean air bubble diameter >

The mean air bubble diameter of foamed sheet used in the present invention is not particularly limited, and preferably 20~150 μm.By for The range of such mean air bubble diameter, so that the arithmetic average roughness Ra for being easy to foam unilateral is adjusted to above range, The waterproofness of adhesive tape improves.

In addition, if the mean air bubble diameter of foamed sheet is 150 μm hereinafter, then applying energetically when recycling to adhesive tape In the case where, it can prevent from being broken using around the big bubble of bubble diameter as starting point.That is, if big in foamed sheet The bubble of bubble diameter is few, then the low density part in foamed sheet tails off, therefore inhibits the rupture generated by the part.This Outside, consider that the mean air bubble diameter of foamed sheet is preferably 20 μm or more from viewpoints such as manufacturing costs.

From the viewpoint of waterproofness and the recycling property raising for making adhesive tape, the mean air bubble diameter of foamed sheet is preferably 140 μm hereinafter, more preferably 120 μm hereinafter, further preferably 100 μm or less.Due to the hair comprising a large amount of stingy bulb diameters The manufacturing cost of bubble piece is got higher, therefore the lower limit value of mean air bubble diameter is preferably 30 μm or more, and more preferably 40 μm or more, into One step is preferably 50 μm or more.

In addition, the mean air bubble diameter in the present invention is will be by the mean air bubble diameter in the direction MD that aftermentioned method measures Average bubble diameter has been carried out with the mean air bubble diameter in the direction TD.

Mean air bubble diameter refers to the value measured by following main points.

Prepare foaming body sample of the foamed sheet as measurement for being cut into 50mm square out.It is impregnated 1 in liquid nitrogen With razor blade along the direction MD and the difference through-thickness cutting of the direction TD after minute.Use digital microscope (Co., Ltd. キーエ Application ス system " VHX-900 ") 200 times of enlarged photographs are shot to its section, to being present in each of the direction MD and the direction TD Whole bubbles of the section of the length 2mm in direction measure bubble diameter, which is repeated 5 times.In turn, by whole bubbles Average value is set as the mean air bubble diameter in the direction MD and the direction TD.

In addition, the direction MD refers to Machine direction (mechanical direction), it is and squeezes out the consistent directions such as direction, And the direction TD refers to Transverse direction (transverse direction), is the direction orthogonal with the direction MD, in the hair of sheet It is in foam (foamed sheet) and unilateral parallel direction.

< expansion ratio >

The expansion ratio of foamed sheet used in the present invention is not particularly limited, preferably 1.2~20cm³/g.By making Expansion ratio is that may be easy to for mean air bubble diameter and 50% compressive strength being adjusted in above range in above range.This Outside, by making expansion ratio 1.2cm³/ g or more, so that flexibility is easy to become well, waterproofness is easy to become good.Separately On the one hand, by for 20cm³For/g hereinafter, to which mechanical strength is got higher, recycling property becomes good.

From the viewpoint of like that, expansion ratio is more preferably 3~14cm³/ g, further preferably 5~13cm³/ g, more Further preferably 7~12cm³/g.In addition, finding out the density of foamed sheet according to JIS K7222 in the present invention, its inverse is set For expansion ratio.

< degree of cross linking >

The degree of cross linking for the foamed sheet being used in the present invention is not particularly limited, preferably 25 mass % or more.If handed over Connection degree is that 25 mass % or more are then easy to for mean air bubble diameter and arithmetic average roughness Ra being adjusted in above range, as As a result, recycling property improves.By for 25 mass % or more, to be easy to for the bubble of foamed sheet miniaturizeing, furthermore each bubble The deviation of size also tail off, recycling property and mechanical strength can be made to improve.In addition, the upper limit value of the degree of cross linking of foamed sheet is excellent It is selected as 70 mass %.Then it is easy to improve expansion ratio if it is such upper limit value, is easy to improve flexibility.From such viewpoint Consider, the degree of cross linking of foamed sheet is more preferably 30~65 mass %, further preferably 40~60 mass %.

The degree of cross linking can be measured by method documented by embodiment.

< independent air bubble rate >

Foamed sheet of the invention is the independent air bubble foamed sheet with independent air bubble, and independent air bubble is relative to whole bubbles Ratio (referred to as " independent air bubble rate ") is 70% or more.Such foamed sheet is easy to ensure waterproofness.Independent air bubble rate is preferably 75% or more, more preferably 90% or more.

Independent air bubble rate can be found out according to ASTM D2856 (1998).Commercially available analyzer can enumerate dry type automatic density Count アキュピッ Network 1330 etc..

More specifically, independent air bubble rate is measured by following main points.It is square that the plane that side length is 5cm is cut out from foamed sheet Shape and certain thickness test film.The thickness of measurement test piece calculates the apparent volume V of test film₁And measurement test piece Weight W₁.Next, calculating apparent volume V shared by bubble based on following formula₂.In addition, constituting the density of the resin of test film It is set as 1g/cm³。

Apparent volume V shared by bubble₂=V₁-W₁

Then, test film is sunk into 23 DEG C of distilled water the depth away from water surface 100mm, test film is applied through 3 minutes Add the pressure of 15kPa.Then, test film is taken out from water and removes the moisture for being attached to test film surface, measurement test piece Weight W₂, continuous air bubbles rate F is calculated based on following formula₁With independent air bubble rate F₂。

Continuous air bubbles rate F₁(%)={ (W₂-W₁)/V₂}×100

Independent air bubble rate F₂(%)=100-F₁

< size >

The thickness of foamed sheet used in the present invention is preferably 0.1~1.5mm.It can if making with a thickness of 1.5mm or less Enough slimmings, can be suitable for the electronic equipment of miniaturization.

From the viewpoint of like that, thickness is preferably 1mm hereinafter, more preferably 0.9mm is hereinafter, further preferably 0.8mm or less.In addition, the lower limit value of thickness is according to the relationship with mean air bubble diameter, preferably 0.1mm or more, more preferably 0.15mm or more.If the waterproofness of foamed sheet and flexibility ensure to become easy with a thickness of 0.1mm or more.

Foamed sheet is preferably the narrow foamed sheet of its width, specifically, it is preferable that be processed into thin-line-shaped foamed sheet.Such as It can make the width 5mm or less of foamed sheet and use, it can be preferably with 3mm hereinafter, more preferably used below with 1mm.This hair Foamed sheet waterproofness used in bright is excellent, therefore can also obtain even if in the case where such as 1mm width is made excellent Waterproofness can be suitble to use in the electronic equipment internal of miniaturization.

The lower limit value of the width of foamed sheet is not particularly limited, and can be the width of such as 0.1mm or more, Ke Yiwei The width of 0.2mm or more.In addition, the flat shape of foamed sheet is not particularly limited, elongate rectangular, frame-shaped, L-shaped, U is made Shape etc. is preferably.However, other than these shapes, or other any shapes such as common quadrangle, circle.

< polyolefin-based resins >

Foamed sheet used in the present invention is preferably made of resin.The type of resin is not particularly limited, from ensuring to foam The flexibility of the appropriateness of piece, while from the viewpoint of being easy to for mean air bubble diameter being adjusted in above range, it preferably comprises poly- Olefin-based resin.

As polyolefin resin, polyvinyl resin, acrylic resin, vinyl-vinyl acetate copolymer etc. can be enumerated, In preferably polyvinyl resin.

(polyvinyl resin)

As polyvinyl resin, can enumerate through Ziegler-Natta compound, Metallocenic compound, chromium oxide compounds Polyvinyl resin obtained by equal polymerization catalysts polymerization is, it is preferable to use the polymerization catalyst polymerization by Metallocenic compound obtains Polyvinyl resin.

In addition, as polyvinyl resin, preferably straight-chain low density polyethylene (LDPE).By using straight-chain low density polyethylene Alkene can assign flexibility to foamed sheet, and can be realized the slimming of foamed sheet.The straight-chain low density polyethylene (LDPE) is more excellent It is selected as the straight-chain low density polyethylene (LDPE) obtained using polymerization catalysts such as Metallocenic compounds.In addition, straight-chain low-density Polyethylene more preferably by by ethylene (for example, relative to whole amount of monomer be 75 mass % or more, preferably 90 mass % with On) be copolymerized with a small amount of alpha-olefin as needed and the straight-chain low density polyethylene (LDPE) that obtains.

As alpha-olefin, specifically, propylene, 1- butylene, 1- amylene, 4-methyl-1-pentene, 1- hexene, 1- can be enumerated Heptene and 1- octene etc..Wherein, the preferably alpha-olefin of carbon atom number 4~10.

Polyvinyl resin, for example above-mentioned straight-chain low density polyethylene (LDPE) density be preferably 0.870~0.910g/cm³, more Preferably 0.875~0.907g/cm³, further preferably 0.880~0.905g/cm³。

As polyvinyl resin, a variety of polyvinyl resins also can be used, furthermore, it is possible to be added above-mentioned density range and Polyvinyl resin other than melting range.

(Metallocenic compound)

As Metallocenic compound, can enumerate with clipping transition metal with the unsaturated compound of pi-electron system The compounds such as bis- (cyclopentadienyl group) metal complexes of structure.More specifically, 1 or 2 or more ring penta can be enumerated Diene basic ring or its analog are present in the transition metal of the tetravalences such as titanium, zirconium, nickel, palladium, hafnium and platinum as ligand (ligand) Compound.

The uniform properties of the active site of such Metallocenic compound, each active site have identical activity degree.Use metal The polymer of cyclopentadinyl compound synthesis is since the uniformity of molecular weight, molecular weight distribution, composition, composition distribution etc. is high, will In the case where piece crosslinking comprising the polymer for using Metallocenic compound to synthesize, it is crosslinked and uniformly carries out.As a result, can be uniform Ground stretches, therefore even if makes foamed sheet is thin to be also easy to keep its thickness uniform.

As ligand, it can be cited for example that, cyclopentadienyl rings, indenyl rings etc..These ring type compounds can by alkyl, Substituted hydrocarbon radical or hydrocarbon-substitution metalloid base replace.As alkyl, can enumerate for example, methyl, ethyl, various propyl, various fourths Base, various amyls, various hexyls, 2- ethylhexyl, various heptyl, various octyls, various nonyls, various decyls, various spermaceti Base, phenyl etc..In addition, so-called " various ", refer to comprising just, secondary, uncle, different various isomers.

In addition it is possible to use ring type compound is polymerized to substance obtained by oligomer as ligand.

Further, other than the unsaturated compound of pi-electron system, the anion of the monovalencies such as chlorine, bromine can also be used to match Body or the anionic cheating ligand of divalent, hydrocarbon, alkoxide, aryl amide, aryl oxide, amide, aryl amide, phosphide (phosphide), diaryl-phosphide etc..

As the transition metal comprising tetravalence, the Metallocenic compound of ligand, can enumerate for example, cyclopentadienyltitanium three (dimethylformamide), methyl cyclopentadienyl titanium three (dimethylformamide), bis- (cyclopentadienyl group) titanium chloride, dimethyl methyl silicon Alkyl tetramethyl-ring pentadienyl-tert-butylamides zirconium dichloride etc..

Metallocenic compound with specific co-catalyst (co-catalyst) by combining, thus in the polymerization of various alkene Play the effect as catalyst.As specific co-catalyst, methylaluminoxane (MAO), borate compounds etc. can be enumerated.Separately Outside, co-catalyst is preferably 10~1,000,000 moles times relative to the use ratio of Metallocenic compound, and more preferably 50~5, 000 mole times.

(acrylic resin)

In addition, can enumerate as acrylic resin for example, polypropylene, propylene-α-alkene containing 50 mass % of propylene or more Hydrocarbon copolymer etc..They can be used alone or two or more kinds may be used.

As the alpha-olefin for constituting propylene-alpha-olefin copolymers, specifically, ethylene, 1- butylene, 1- penta can be enumerated Alkene, 4-methyl-1-pentene, 1- hexene, 1- heptene, 1- octene etc., wherein the preferably alpha-olefin of carbon atom number 6~12.

(vinyl-vinyl acetate copolymer)

The vinyl-vinyl acetate copolymer used as polyolefin resin can be enumerated for example, excellent containing vinyl acetate It is selected as 6~40 mass %, more preferably 12~35 mass %, the further preferably ethane-acetic acid ethyenyl of 20~33 mass % Ester copolymer.

It in the present invention, for example, can be by different 2 such as molecular weight, the amount of the vinyl acetate of copolymer composition, fusing points Kind or more copolymer in combination use.

In addition, vinyl-vinyl acetate copolymer used in the present invention can in addition to ethylene and vinyl acetate with Outside, the copolymer of the vinyl alcohol also generated comprising hydrolyzing a part of vinyl acetate.

As such vinyl-vinyl acetate copolymer, can enumerate for example, Dong ソー Co. Ltd. system " ウ Le トラセ Application ", three well デュ Port Application Port リケミカ Le Co. Ltd. systems " エバ Off レッ Network ス ", Ube Industries, Ltd system " UBE Port リエチレ Application ", Asahi Chemical Industry's ケミカ Le ズ Co. Ltd. system " サ Application テッ Network " etc..

(content of each resin)

In the case where using polyvinyl resin as polyolefin resin, the amount of polyvinyl resin is relative to composition foamed sheet Resin total amount be preferably 50 mass % or more, more preferably 60 mass % or more, further preferably 70 mass % or more can Substantially only to include polyvinyl resin.If the content of polyvinyl resin is 50 mass % or more, waterproofness and recycling Property improve.

In foamed sheet comprising polyolefin resin as resin in the case where, the resin contained by foamed sheet can individually make With polyolefin resin, but it also may include the resin other than polyolefin resin.In foamed sheet, other than comprising polyolefin resin Resin in the case where, the ratio of the resin total amount relative to polyolefin resin is preferably 60 mass % or more, more preferably 70 Quality % or more, further preferably 80 mass % or more.

In addition, polystyrene thermoplastic elastic can be enumerated as the resin other than polyolefin resin used in foamed sheet Various elastomers, the rubber constituents such as the ethylene, propylenes based thermoplastic elastomer such as body, EPDM etc..

(thermal decomposable foaming agent)

Foamed sheet of the invention preferably passes through will be comprising the expandable composition hair of above-mentioned resin and thermal decomposable foaming agent Bubble is to manufacture.In addition, as thermal decomposable foaming agent, it is preferable to use thermal decomposable foaming agent of the partial size less than 18 μm.In this hair In bright, thermal decomposable foaming agent by using partial size less than 18 μm, in addition, the degree of cross linking is adjusted to particular range, so as to To be adjusted to the range of above-mentioned mean air bubble diameter, as a result, the recycling property of adhesive tape can be made to improve.From such viewpoint Considering, the partial size of thermal decomposable foaming agent is preferably 2~17 μm, and more preferably 5~16 μm.

In addition, the partial size of thermal decomposable foaming agent refers to the value measured by laser diffractometry, and it is comparable to accumulate The partial size (D50) of frequency 50%.

As thermal decomposable foaming agent, it is able to use organic foaming agent, inorganic foaming agent.As organic foaming agent, can lift The azo-compounds, N such as azodicarboamide, azodicarboxy acid metal salt (barium azodicarboxylate etc.), azodiisobutyronitrile out, The nitroso compounds such as N '-dinitrosopentamethylene tetramine, biruea, 4,4 '-oxygroups bis- (benzene sulfonyl hydrazides), toluene sulfonyl hydrazide Semicarbazide compounds such as equal hydrazine derivates, toluene sulfonyl semicarbazide etc..

As inorganic foaming agent, can enumerate sour ammonium, sodium carbonate, ammonium hydrogen carbonate, sodium bicarbonate, ammonium nilrite, sodium borohydride, Citric anhydride list sodium etc..

Wherein, from the viewpoint and economy for obtaining fine bubble, from the viewpoint of secure context, preferably azo Close object, more preferably azodicarboamide.They can be used alone or two or more kinds may be used.

The use level of thermal decomposable foaming agent in expandable composition is relative to 100 mass parts of resin, and preferably 1~20 Mass parts, more preferably 3~18 mass parts, further preferably 5~15 mass parts.

In addition, expandable composition preferably other than above-mentioned resin and thermal decomposable foaming agent, also contains nuclei of bubbles tune Save agent.As nuclei of bubbles regulator, the organic compound of the zinc compounds such as zinc oxide, zinc stearate, citric acid, urea can be enumerated Deng, wherein more preferably zinc oxide.By also using nuclei of bubbles regulator other than the foaming agent of above-mentioned small particle, easily In keeping mean air bubble diameter small, the deviation of bubble diameter can be inhibited.The use level of nuclei of bubbles regulator is relative to 100 matter of resin Measuring part is preferably 0.1~8 mass parts, more preferably 0.2~5 mass parts, further preferably 0.3~2.5 mass parts.

Expandable composition in addition to the above ingredients, can also contain antioxidant, heat stabilizer, coloring as needed Agent, fire retardant, antistatic agent, filling material etc. are generally used in the additive of foaming body.

(manufacturing method of independent air bubble foamed sheet)

The manufacturing method of independent air bubble foamed sheet used in adhesive tape of the invention is not particularly limited, for example, can be with By will include that the expandable composition of resin and thermal decomposable foaming agent is crosslinked, carrying out heating sends out thermal decomposable foaming agent Bubble, manufactures along at least one stretching in the direction TD and the direction MD.More specifically, which includes the following process (1) ~(4).

Process (1): by resin, thermal decomposable foaming agent, as needed the nuclei of bubbles regulator and other additives that cooperate Mixing, the process for being shaped to the expandable composition (resin sheet) of sheet

Process (2): the process for being crosslinked expandable composition the expandable composition irradiation ionization property radioactive ray of sheet

Process (3): the expandable composition of crosslinking is heated, thermal decomposable foaming agent is made to foam, and obtains foamed sheet Process

Process (4): the process for stretching foamed sheet along the direction of either or both of the direction MD or the direction TD

In process (1), the molding method of resin sheet is not particularly limited, as long as example, resin, heat decomposition type are sent out Infusion, the nuclei of bubbles regulator cooperated as needed and other additives are supplied to extruder and carry out melting mixing, from extruder Expandable composition is extruded as sheet and carrys out moulding resin piece.

As the method for being crosslinked expandable composition in process (2), penetrated using to resin sheet irradiation electron ray, α The method of the ionization property radioactive ray such as line, β ray, gamma-rays.As long as the exposure of above-mentioned ionizing radiation is with resulting foamed sheet The degree of cross linking become above-mentioned desired range mode adjust, preferably 5~15Mrad, more preferably 6~ 13Mrad。

In process (3), as long as heating temperature when making thermal decomposable foaming agent foam expandable composition heating is It is more than the blowing temperature of thermal decomposable foaming agent, but preferably 200~300 DEG C, more preferably 220~280 DEG C.

The stretching of foamed sheet in process (4) can be carried out along both directions MD and TD, can also only be carried out along one, but It is preferred that being carried out along the two.Furthermore the stretching of foamed sheet can carry out after obtaining foamed sheet making resin sheet foam, can also be Progress while making resin sheet foam.In addition, so that resin sheet is foamed and in the case where obtaining and stretching foamed sheet after foamed sheet, It can not directly continue foamed sheet cooling to stretch foamed sheet in the case where maintaining molten condition when foaming, can also will foam After piece is cooling, melting or soft state post-tensioning foamed sheet is made in foamed sheet heating again.Foamed sheet is easy to by stretching Form thin thickness.

In process (4), foamed sheet to the stretching ratio in one of the direction MD and the direction TD or both be preferably 1.1~ 5.0 times, more preferably 1.2~4.0 times, further preferably 1.5~3.3 times.Wherein, particularly preferably make the stretching times to the two Rate is within the scope of these.By being easy to make the desired range of 50% compressive strength for such range.

In addition, if making the above-mentioned lower limit value of stretching ratio or more, then the flexibility of foamed sheet is easy to become good.It is another Aspect if it is upper limit value hereinafter, can then foamed sheet be prevented to be broken in stretching, or be leaked out from the foamed sheet in foaming and is foamed Gas and expansion ratio significantly reduce, and the flexibility of foamed sheet becomes well, and quality is also easy to uniformly.

In addition, as long as foamed sheet is heated to such as 100~280 DEG C, preferably 150~260 DEG C when stretching.

The foamed sheet for operating and obtaining like that above can be cut off by the known method such as punch process, be processed into and wished The shape of prestige.

However, this manufacturing method is not limited to the above method, pass through method other than the above, it is also possible to obtain foamed sheet. For example, can cooperate organic peroxide in advance in expandable composition by replacing irradiation ionization property radioactive ray, will foam Property composition heating be crosslinked organic peroxide decomposition method etc..

(adhesive phase)

Adhesive tape of the invention is provided with adhesive phase in at least one side of foamed sheet.Have by the adhesive phase aftermentioned Peel strength and thickness, so that the waterproofness of adhesive tape becomes good.

(peel strength)

The peel strength of adhesive phase is 1.1N/25mm or more.The adhesive tape pair if peel strength is less than 1.1N/25mm The adaptation of adherend reduces, and waterproofness is deteriorated.From make adhesive tape waterproofness it is good from the viewpoint of, the removing of adhesive phase Intensity is preferably 1.5N/25mm or more, more preferably 2N/25mm or more, further preferably 3N/25mm or more.From making to bond From the viewpoint of the recycling property of band improves, the peel strength of adhesive phase is preferably 20N/25mm hereinafter, more preferably 15N/ 25mm is hereinafter, further preferably 10N/25mm or less.The peel strength of adhesive phase can be by constituting the viscous of adhesive phase Type of mixture etc. adjusts.

In addition, the peel strength of so-called adhesive phase, refers to according to 90 degree at 25 DEG C of JIS Z0237-2009 measurement Peel off bonding force.

In the present invention, in the case where being provided with adhesive phase on one side, the bonding of the one side only is set in foamed sheet Oxidant layer meets above-mentioned peel strength.In the case where the two sides of foamed sheet is provided with adhesive phase, can only one side adhesive Layer meets above-mentioned peel strength, can also meet above-mentioned peel strength with the adhesive phase on two sides.

(thickness)

Adhesive phase used in adhesive tape of the invention with a thickness of 10 μm or more.If it is less than 10 μm, then with glued Closely sealed between object becomes inadequate, and waterproofness is deteriorated.From the viewpoint of keeping waterproofness good, the thickness of adhesive phase is preferred It is 15 μm or more, more preferably 18 μm or more.In addition, from the viewpoint of the electronic equipment use to miniaturization, adhesive phase It is preferably thin to a certain degree, specifically, adhesive phase is preferably 55 μm hereinafter, more preferably 50 μm or less.If using this The certain thickness of sample adhesive phase below, even if then in the component that adhesive tape is compressed to and is inserted into narrow electronic equipment Between in the case where, repulsive force is also low, can prevent the deformation etc. of component.

Adhesive tape is in the case where foamed sheet two sides has adhesive phase, as long as only the adhesive phase of one side meets above-mentioned thickness Degree, but from the viewpoint for keeping the overall thickness of adhesive tape thin, from the viewpoint of reducing repulsive force, the preferred adhesive phase on two sides Meet above-mentioned value.

(adhesive)

Adhesive phase is preferably formed by adhesive described below.It as adhesive, is not particularly limited, for example, can be with Using acrylic adhesive, carbamate system adhesive, elastomeric adhesive etc., from the viewpoint of recycling property and waterproofness Consider, preferably acrylic adhesive.

In the present invention, in the case where adhesive tape has adhesive phase on foamed sheet two sides, 2 adhesive phases are used Adhesive can be the same or different.

(acrylic adhesive)

Hereinafter, the embodiment to acrylic adhesive used in adhesive phase is described in more detail.Acrylic acid Be adhesive be containing will comprising (methyl) alkyl acrylate system monomer (A) polymerizable monomer polymerization obtained by acrylic acid series The adhesive of polymer.

In addition, in the present specification, so-called term " (methyl) alkyl acrylate ", refer to comprising alkyl acrylate, With the concept of both alkyl methacrylates, other similar terms are also the same.In addition, term " polymerizable monomer ", not only It is only the compound without repetitive unit, as long as being with the compound of (methyl) alkyl acrylate system monomer (A) copolymerization Can, there is aftermentioned other monomers itself the compound of repetitive unit to be also included in the concept of term " polymerizable monomer ".

(methyl) alkyl acrylate system monomer (A)

(methyl) alkyl acrylate system monomer (A) is preferably the ester of (methyl) acrylic acid and aliphatic alcohol, and is rouge The carbon atom number of the alkyl of fat race alcohol is preferably 2~14, the Arrcostab in more preferably 4~10 aliphatic alcohol source.If alkane The carbon atom number of base is then to be easy to peel strength being adjusted to above range within the scope of this.

As specific (methyl) alkyl acrylate system monomer (A), can enumerate for example, (methyl) ethyl acrylate, (first Base) n-propyl, (methyl) isopropyl acrylate, (methyl) n-butyl acrylate, (methyl) isobutyl acrylate, (first Base) tert-butyl acrylate, (methyl) amyl acrylate, (methyl) Hexyl 2-propenoate, (methyl) heptylacrylate, (methyl) propylene Sour 2- ethylhexyl, (methyl) n-octyl, (methyl) Isooctyl acrylate monomer, (methyl) nonyl acrylate, (methyl) third Olefin(e) acid last of the ten Heavenly stems ester, (methyl) acrylic acid hendecane base ester, (methyl) dodecylacrylate, (methyl) acrylic acid tridecyl Ester and (methyl) acrylic acid tetradecane base ester etc..

Wherein, preferably (methyl) n-butyl acrylate, (methyl) Hexyl 2-propenoate, (methyl) heptylacrylate, (first Base) 2-EHA, (methyl) n-octyl, more preferably (methyl) n-butyl acrylate, (methyl) propylene Sour 2- ethylhexyl or their combination.

(methyl) alkyl acrylate system monomer may be used alone, or two or more kinds may be used in combination.

Component units from (methyl) alkyl acrylate system monomer (A) constitute principal component in adhesive, contain Amount in terms of adhesive total amount benchmark be generally 30 mass % or more, preferably 40 mass % or more, more preferably 45 weight % with On.In this way, if keeping the content of (methyl) alkyl acrylate system monomer (A) more, it can be to desired by adhesive imparting Bonding force.

In addition, the content of the Component units from (methyl) alkyl acrylate system monomer (A) in adhesive is with after The content of (methyl) alkyl acrylate system monomer (A) in the adhesive composition stated is substantially the same, therefore can replace It indicates.It is also the same about the ingredient other than (A) ingredient described below.

Vinyl monomer (B) containing polar group

Polymerizable monomer also contains preferably other than (methyl) alkyl acrylate system monomer (A) and contains polar group Vinyl monomer (B).Vinyl monomer (B) containing polar group has polar group and vinyl.By being used in adhesive phase Monomer (B) containing polar group, to be easy to adjust peeling bonding force of adhesive phase etc..

As the vinyl monomer (B) containing polar group, such as (methyl) acrylic acid and itaconic acid etc. can be enumerated and contain second The carboxylic acid of alkenyl and its acid anhydride, the vinyl monomer with hydroxyl, the vinyl monomer containing nitrogen etc..

As the vinyl monomer with hydroxyl, (methyl) acrylic acid 2- hydroxy methacrylate, (methyl) acrylic acid 2- can be enumerated Hydroxy propyl ester, (methyl) acrylic acid 4- hydroxybutyl, caprolactone modification (methyl) acrylate, polyoxyethylene (methyl) acrylic acid Ester and polyoxypropylene (methyl) acrylate etc..

As the vinyl monomer containing nitrogen, can enumerate (methyl) acrylonitrile, n-vinyl pyrrolidone, N- vinyl oneself Lactams, N- vinyl lauric lactam, (methyl) acryloyl morpholine, (methyl) acrylamide, dimethyl (methyl) propylene Amide, N- methylol (methyl) acrylamide, N- butoxymethyl (methyl) acrylamide and dimethylaminomethyl (methyl) Acrylate etc..

In vinyl monomer (B) containing polar group, preferably (methyl) acrylic acid and itaconic acid etc. contain vinyl Carboxylic acid and its acid anhydride, more preferably (methyl) acrylic acid, further preferably acrylic acid.These contain the vinyl list of polar group Body (B) may be used alone, or two or more kinds may be used in combination.

In the case where using vinyl monomer (B) containing polar group, is derived from adhesive and contain polar group The content of the Component units of vinyl monomer (B) is relative to the composition list for deriving from (methyl) alkyl acrylate system monomer (A) First 100 mass parts are preferably 1~15 mass parts, more preferably 2~12 mass parts, further preferably 3~10 mass parts.Pass through In the range for keeping the content of the vinyl monomer (B) containing polar group such, to be easy to the Tg of adhesive phase, agglutination Power, bonding force etc. are adjusted to range appropriate.

Other monomers

Polymerizable monomer may include other monomers other than above-mentioned (A) and (B).As other monomers, benzene can be enumerated Vinyl esters of carboxylic acids such as vinyl monomer, polyfunctional monomer, vinyl acetate etc..As styrenic monomers, can enumerate for example, Styrene, α-methylstyrene, o-methyl styrene and p-methylstyrene etc..

In addition, the monomer with 2 or more vinyl can be enumerated as polyfunctional monomer, can preferably enumerate with 2 with The multifunctional (methyl) acrylate of upper (methyl) acryloyl group.If using polyfunctional monomer, acrylic acid series polymeric compounds energy Enough form reticular structure.

As specific polyfunctional monomer, hexylene glycol two (methyl) acrylate, polyethylene glycol two (methyl) third can be enumerated Olefin(e) acid ester, polypropylene glycol two (methyl) acrylate, Ethoxylated bisphenol A bis- (methyl) acrylate, three (2- hydroxyethyls) Isocyanurate triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylation trimethylolpropane tris third Olefin(e) acid ester, propoxylated glyceryl triacrylate, NPGA neopentyl glycol adipate diacrylate etc..

Using other monomers, in adhesive, the content from the Component units of other monomers is opposite In source (methyl) alkyl acrylate system monomer (A) 100 mass parts of Component units be 0.5~15 mass parts, more preferably 1 ~7 mass parts, further preferably 1~5 mass parts.

The weight average molecular weight of acrylic acid series polymeric compounds measured by GPC method is not particularly limited, and for example, 200,000~100 Ten thousand, preferably 400,000~900,000.

(tackifying resin)

From the viewpoint of improving bonding force, acrylic adhesive can contain tackifying resin.As tackifying resin, The preferably Inhibition of polymerization such as hydrogenated terpene resin, hydrogenated rosin, disproportionated rosin resin, rosin ester based polymer, Petropols Low tackifying resin.Wherein, inhibit polymerization reaction, therefore the increasing of preferably rosin series if tackifying resin has a large amount of double bonds Viscosity resin, wherein preferably rosin ester based polymer.

From make adhesive cohesive force and bonding force improve from the viewpoint of, as long as the softening point of tackifying resin be 95 DEG C with Upper degree, but preferably comprising softening point is 120 DEG C or more of tackifying resin, for example, can be used together softening point be 95 DEG C with The upper and tackifying resin less than 120 DEG C and softening point are 120 DEG C or more and 150 DEG C of tackifying resins below.In addition, softening point As long as the ring and ball method by JISK2207 defined measures.

The content of tackifying resin in acrylic adhesive is preferably 2 relative to 100 mass parts of acrylic acid series polymeric compounds ~40 mass parts, more preferably 4~35 mass parts, further preferably 5~25 mass parts.

(crosslinking agent)

In the case where the resin for constituting acrylic adhesive has hydroxyl, carboxyl, from the viewpoint for improving adhesiveness Consider, cross-linked structure can be formed between main chain by using crosslinking agent.

As crosslinking agent, can enumerate for example, isocyanates system crosslinking agent, epoxy crosslinking agent, aziridine system crosslinking agent and Metal chelate crosslinking agent etc..Wherein, preferably isocyanates system crosslinking agent, epoxy crosslinking agent.

As isocyanates system crosslinking agent, can enumerate for example, polyisocyanate compound.As polyisocyanate compound Concrete example, the fragrance such as toluene di-isocyanate(TDI), methyl diphenylene diisocyanate, benzene dimethylene diisocyanate can be enumerated The aliphatic polyisocyantes such as race's polyisocyanates, hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated diphenyl Alicyclic polyisocyanates such as methane diisocyanate etc..In addition, can also enumerate their biuret body, isocyanuric acid ester body, And as with the low molecules active hydrogen-contg compound such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, castor oil Adduction body of reactant etc..

They can be used alone, two or more can also be applied in combination.

As epoxy crosslinking agent, can enumerate for example, bisphenol A type epoxy compound, bisphenol F type epoxy compound, 1,3- Bis- (N, N- diglycidyl amino methyl) toluene, N, N, N ', N '-four glycidyl group -4,4- diaminodiphenyl-methane, N, N, N ', N '-four glycidyl group m-xylene diamine, 1,3- bis- (N, N- diglycidyl amino methyl) hexamethylenes, 1,6- Diglycidyl n-hexane etc..

The peel strength of adhesive phase used in the present invention can be adjusted by the amount of crosslinking agent.

From the viewpoint of the range for being readily adjusted to above-mentioned peel strength, use level from crosslinking agent to adhesive relative to 100 mass parts of acrylic acid series polymeric compounds are preferably 0.5 mass parts or more, more than more preferably 1 mass parts, also, it is preferred that being 7 matter Part is measured hereinafter, more preferably 5 below the mass.

(other ingredients)

The acrylic adhesive being used in the present invention in addition to the above ingredients, can also contain plasticizer, softening Agent, pigment, dyestuff, Photoepolymerizationinitiater initiater, fire retardant etc. are used in the various additives of adhesive in the past.

(elastomeric adhesive)

Elastomeric adhesive contains rubber constituent, as rubber constituent, it is preferable to use styrene-isoprene block copolymerization Object.The diblock rate of styrene-isoprene block copolymer is preferably 25~70 mass %, more preferably 30~65 matter Measure %, further preferably 45~60 weight %.Here so-called diblock, refer to formed by styrene and isoprene it is two embedding Section.Styrene-isoprene block copolymer becomes 25% or more by diblock rate and shows sufficient bonding force, in addition, By being easy to improve shear strength for 70 mass % or less.In addition, styrene-isoprene block copolymer contains in addition to two Other than block, also there is the copolymer of the blocks such as 3 or more the three blocks formed by styrene, isoprene, styrene block.

Styrene amount in styrene-isoprene block copolymer is not particularly limited, preferably 14~24 mass %, More preferably 15~18 mass %.If styrene amount is 14 mass % or more, becomes the high adhesive of compendency, be easy to mention High shear strength.In addition, if being 24 mass % hereinafter, then cohesive force becomes appropriate size and is easy to show bonding force.

The molecular weight of styrene-isoprene block copolymer is not particularly limited, in terms of matter average molecular weight preferably 100,000~400,000, more preferably 150,000~250,000.In addition, so-called matter average molecular weight here, refers to and passes through GPC The value that (gel permeation chromatography) method is measured as polystyrene conversion molecular weight.

Elastomeric adhesive preferably other than above-mentioned rubber constituent, further contains tackifying resin.Elastomeric adhesive Various tackifying resins can be used in used tackifying resin, but it is preferable to use petroleum line resin, terpene resin, coumarone trees Rouge.Tackifying resin can be used alone or two or more kinds may be used, but petroleum line resin is preferably used in combination and is selected from terpenes It is at least one kind of in resin and coumarone resin.The combination of tackifying resin in this way and be easy to for peel strength being adjusted to State range.

As petroleum line resin, can enumerate fatty family Petropols (C5 through-stone oleoresin), alicyclic ring family Petropols, Aromatic system Petropols etc., it is preferably fatty from the viewpoint of the compatibility with styrene-isoprene block copolymer Family Petropols.In addition, it is preferable to use the petroleum line resins that softening point is 90~120 DEG C or so for petroleum line resin.

In addition, as terpene resin, the terpene resin that softening point is 80~120 DEG C or so can be used, but from bonding force From the viewpoint of ensuring, preferably less than 100 DEG C of terpene resin.In addition, as coumarone resin, in order to ensure cohesive force, It the use of softening point is preferably 110~130 DEG C, more preferably 115~125 DEG C of coumarone resin.

Tackifying resin is preferably 60~250 mass parts relative to 100 mass parts of rubber constituent, more preferably 100~200 matter Measure part, further preferably 110~180 mass parts.By making the use level of tackifying resin within the above range, so as to so that Cohesive force is good and assigns the peeling bonding force of appropriateness.

In addition, and with petroleum line resin, at least one kind of in terpene resin and coumarone resin in the case where, Petroleum line resin is preferably 50~200 mass parts relative to 100 mass parts of rubber constituent, preferably 60~150 mass parts, more excellent It is selected as 60~110 mass parts.On the other hand, terpene resin is relative to 100 mass parts of rubber constituent, preferably 10~70 mass Part, more preferably 20~60 mass parts, further preferably 30~50 mass parts.Further, coumarone resin is relative to rubber 100 mass parts of ingredient, preferably 10~60 mass parts, more preferably 15~50 mass parts, further preferably 20~40 mass Part.

Elastomeric adhesive can contain softening agent, antioxidant, filler etc. as needed.

(carbamate system adhesive)

Carbamate system adhesive is not particularly limited, and can enumerate for example, being at least esterified polyalcohol and polyisocyanic acid The carbamate resins etc. for closing object reaction and obtaining.As above-mentioned polyalcohol, can enumerate for example, polyether polyol, polyester it is more First alcohol, polycarbonate polyol, polycaprolactone polyol etc..As above-mentioned polyisocyanate compound, can enumerate for example, hexichol Dicyclohexylmethane diisocyanate, toluene di-isocyanate(TDI), hexamethylene diisocyanate etc..These carbamate system adhesives can be with It is used alone, also two or more kinds may be used.

In addition, can be used makes polyurethane polyol and polyfunctional isocyanate system as carbamate system adhesive The carbamate resins of curing agent reaction and acquisition.Polyurethane polyol, which can be enumerated, makes above-mentioned polyalcohol and polyisocyanates Polyurethane polyol obtained by compound reaction or react polyalcohol and polyisocyanate compound with cahin extension agents such as diamines and The polyurethane polyol obtained.As polyfunctional isocyanate system curing agent, as long as the chemical combination with 2 or more isocyanate group Above-mentioned isocyanate compound can be used in object.

Carbamate system adhesive can also contain above-mentioned particle, in addition, amino other than carbamate resins Formic acid esters system adhesive can contain tackifying resin, softening agent, antioxidant, filler etc. as needed.

(manufacturing method of adhesive phase)

It can be by that will include using acrylic adhesive about the adhesive for constituting adhesive phase Then the heating of the adhesive composition of above-mentioned polymerizable monomer and polymerization initiator, reflux, crosslinked polymer are obtained.This Outside, also polymerizable monomer polymerization can be made to obtain by the adhesive composition irradiation light comprising above-mentioned polymerizable monomer.

Adhesive composition may include at least one kind of of above-mentioned tackifying resin, particle and other ingredients as needed.

It is not particularly limited, can be enumerated for example, using coating in the method that at least one side of foamed sheet forms adhesive phase The method of the coating machines coating adhesive such as machine, the method for being sprayed adhesive using sprayer, being coated with are coated with bonding using hairbrush The method of agent, method that the adhesive phase formed on stripping film is transferred to foamed sheet etc..

The purposes > of < adhesive tape

The purposes of adhesive tape is not particularly limited, since waterproofness is excellent, preferably as such as electronic equipment internal Sealing material use.Furthermore, it is possible to be suitble to use inside the small various mancarried electronic aids in the gap of configuration foamed sheet.As Electronic equipment can enumerate liquid crystal display, organic el display, portable phone, camera, game station, electronic documentation, individual Computer etc..

In the present invention, adhesive tape, which passes through, to be configured as described above between 2 components for constituting electronic equipment, it can be ensured that Adaptation between this 2 components.

Embodiment

Illustrate the present invention in further detail by embodiment, but the present invention is not by any restriction of these examples.

[measuring method]

The measuring method of each physical property and evaluation method is as follows described.

< arithmetic average roughness Ra >

The arithmetic average roughness of foamed sheet passes through laser microscope (キーエ Application ス according to JIS B 0601 (2001) Society's system, " VK-8500 ") measurement.

In addition, the measurement of arithmetic average roughness Ra to make adhesive phase formed before foamed sheet two sides carry out.

< interlaminar strength >

Fig. 1 shows the schematic diagrames of the experimental rig for evaluating interlaminar strength.It is applied in the 25mm square range of foamed sheet 11 After cloth silane coupling agent (セメダイ Application Co. Ltd. system " PPX プライマー "), it is added dropwise diameter 5mm's in the center of coated portion Bonding agent 12 (セメダイ Application Co. Ltd. system " PPX ").The aluminium that 25mm square is placed in part is added dropwise in bonding agent immediately after Fixture 13 processed crimps foamed sheet with fixture 13.Then, foamed sheet is cut along the size of fixture 13.In the foamed sheet of cutting Non- bonding jig 13 face be coated with silane coupling agent, coated portion center be added dropwise diameter 5mm bonding agent 12.Exist immediately after The aluminum fixture 14 that 10mm square is placed in part is added dropwise in bonding agent, and foamed sheet is crimped with fixture 14.It will be on the periphery of fixture 14 After the bonding agent of exudation is wiped, notch 15 is introduced to foamed sheet along the size of fixture 14.It is placed 30 minutes at room temperature Bonding agent is conserved, as interlaminar strength test sample.

Then, to testing machine (Co., Ltd. エーア Application De デイ system " テ of the load cell provided with 1kN Application シロ Application universal testing machine "), interlaminar strength is installed in the unilateral mode vertical relative to draw direction of foamed sheet and is surveyed Surely sample is used.One side of fixture was stretched vertically upward with speed 100mm/ minutes, only make the range of the 1cm square of foamed sheet into Row splitting.The maximum loading of measurement at this time, as the 1st measurement result.Same operation is repeated 3 times, is put down Mean value is set as interlaminar strength.

< expansion ratio >

About foamed sheet, apparent density is measured according to JIS K7222, its inverse is set as expansion ratio.

< mean air bubble diameter >

The mean air bubble diameter of foamed sheet is measured by the method that specification is recorded.

50% compressive strength > of <

About foamed sheet, 25% compressive strength is determined according to JIS K6767.

< degree of cross linking >

From the test film of foaming piece collection about 100mg, the weight A (mg) of precision weighing test film.Next, by the test Dimethylbenzene 30cm of the piece at 120 DEG C³Middle dipping and after placing 24 hours, is taken on metal mesh with the metal mesh filter of 200 mesh Insoluble ingredient, vacuum drying, precision weighing do not dissolve ingredient weight B (mg).By resulting value, calculated by following formula The degree of cross linking (quality %).

The degree of cross linking (quality %)=(B/A) × 100

< independent air bubble rate >

The independent air bubble rate of foamed sheet is measured by the method that specification is recorded.

< peel strength >

The bonding force of adhesive phase is to have carried out bonding force when 90 ° of disbonded tests according to JIS Z 0237.It is specific and Speech, bonding sheet is crimped with SUS plate, 90 degree of peeling bonding forces when measuring at 25 DEG C with speed removing in 300mm/ minutes.

< waterproofness >

Waterproofing property evaluation passes through the examination that under conditions of 23 DEG C of temperature, relative humidity 50%, will make by following methods It tests sample and sinks to depth of water 10cm, the presence or absence of visual confirmation immersion carries out.

In addition, in this waterproofing property evaluation, after making test specimen, under conditions of 23 DEG C of temperature, relative humidity 50% Maintenance carries out after 6 hours.

Evaluation criteria is will to be set as the case where the inside of frame shape is not soaked after 1 hour after sinking to depth of water 10cm 30 minutes are not had the case where soaking, soaking within 1 hour to set the case where being set as " A ", will soak within 30 minutes by " S " It is evaluated for " B ".

(production of test specimen)

It is vertical 60mm × horizontal 40mm, the frame shape that width is 1.0mm that adhesive tape, which is punched into periphery,.It then, will be resulting The adhesive tape of frame-shaped with arithmetic average roughness Ra is 1.0 μm, 2 blocks of acrylic acid tie-plates that maximum height roughness Rz is 5.0 μm It clips.In turn, with bolt fastening until the gap between 2 blocks of acrylic acid tie-plates becomes half.

Then, which is sunk into depth of water 10cm by the above method, visual confirmation is in the inside water of frame-shaped No immersion.

< recycling property evaluation test >

Adhesive tape is cut into length 30cm, width 25mm, in such a way that air does not enter, on SUS plate, makes adhesive tape Adhesive phase contact, on adhesive tape load 2kg roller and it is reciprocal 2 back and forth, adhesive phase is crimped with SUS plate.Then, Disbonded test is carried out with 300mm/min using cupping machine (テ Application シロ Application), is shelled at the interface of adhesive phase and SUS plate From " A: flawless " being evaluated as if not remaining foaming body on SUS plate after removing, if after removing on SUS plate Residual foaming body is then evaluated as " B: crackle ".

[resin]

Resin used in the present embodiment described below.

Resin A (LLDPE): straight-chain ldpe resin (LLDPE) (エ Network ソ Application ケミカ Le society system, quotient The name of an article " EXACT3027 ", density: 0.900)

[manufacture of adhesive phase]

The manufacture > of < adhesive phase A

70 mass parts of butyl acrylate, acrylic acid 2- second are put into the reactor for having thermometer, blender, cooling tube Own 25 mass parts of ester of base and 5 mass parts of acrylic acid are further added 80 mass parts of ethyl acetate, have carried out nitrogen displacement.Then, Reactor is heated and starts to flow back.Then, in above-mentioned reactor, the azodiisobutyronitrile as polymerization initiator is added 0.1 mass parts flow back 5 hours at 70 DEG C, obtain the solution of acrylic acid series copolymer.

About resulting acrylic acid series copolymer, uses Water society system " 2690SeparationsModel " as column, lead to It crosses GPC method and determines weight average molecular weight, result is 500,000.

In the solution of resulting acrylic acid series copolymer (100 mass parts) cooperate 1 mass parts of isocyanates system crosslinking agent, 10 mass parts of polymer of rosin ester system, are stirred, to obtain adhesive.The adhesive is coated on as described later de- On mould paper, make it dry to obtain adhesive phase A.

The manufacture > of < adhesive phase B

Butyl acrylate is changed to 55 mass parts, 2-EHA is changed to 40 mass parts, by isocyanic acid Ester system crosslinking material is changed to 3 mass parts, and the polymer of rosin ester system is changed 5 parts, in addition to this, by with above-mentioned adhesive phase The same method of A obtains adhesive.The adhesive is coated on as described later on processing release paper and is made it dry, to obtain viscous Mixture layer B.

The composition etc. of each adhesive phase is shown in Table 1.

Table 1

[embodiment 1]

(manufacture of foamed sheet)

8 mass of azodicarboamide for being 15 μm by 100 mass parts of Resin A, as the partial size of thermal decomposable foaming agent Part, as zinc oxide (Sakai Chemical Industry Co., Ltd.'s system, trade name " OW-212F ") 1 mass parts of nuclei of bubbles regulator and anti- 0.5 mass parts of oxidant are supplied to extruder, the melting mixing at 130 DEG C, and resulting expandable composition is squeezed out strip The resin sheet of shape.

Next, will set the electron ray 9Mrad of the two sides irradiation acceleration voltage 500kV of the resin sheet of above-mentioned strip After the crosslinking of rouge piece, the resin sheet of crosslinking is continuously fed to be maintained at 250 DEG C of foaming by hot wind and infrared heater Heating is carried out in furnace makes its foaming, obtains foamed sheet.

Then, resulting foamed sheet is continuously sent out from foaming furnace.In turn, foamed sheet is maintained with the temperature on its two sides In the state of 200~250 DEG C, stretch foamed sheet with 2.5 times of stretching ratio along its direction TD, and with foamed sheet to hair The feeding speed (feed speed) of bubble furnace winds foamed sheet compared to fast winding speed to draw foamed sheet also along the direction MD Reach 2.0 times.The foamed sheet (thickness: 500 μm) of embodiment 1 is obtained as a result,.In addition, the winding speed of above-mentioned foamed sheet is examined It is adjusted caused by the foaming for considering resin sheet itself to the swell increment in the direction MD.By resulting foamed sheet according to above-mentioned evaluation side Method evaluation, the results are shown in table 1.

(manufacture of adhesive tape)

The processing release paper for preparing 150 μm of thickness, the adhesive to form adhesive phase is coated in the demoulding process face of the processing release paper (A), 5 minutes dry at 100 DEG C, to form 20 μm of thickness of adhesive phase, it is bonded with the one side of foamed sheet.Obtain use The processing release paper that 150 μm of thickness covers the adhesive tape of single side.

[embodiment 2~9 and comparative example 1~3]

The composition of expandable composition, electronbeam irradiation condition, the type of adhesive phase, thickness etc. is as shown in table 2 It changes like that, in addition to this, operates similarly with example 1 and obtain foamed sheet and adhesive tape.The stretching ratio of MD and TD It is adjusted in the range of 1.5~3.0.Resulting foamed sheet is evaluated according to above-mentioned evaluation method, the results are shown in table 2 In.

By embodiment it is found that the waterproofness of adhesive tape of the invention is good.It is further known that making to foam in embodiment In the case that the interlaminar strength of piece is a certain range, recycling property becomes good.In contrast, it is unsatisfactory for important document of the invention Adhesive tape shown in comparative example becomes the result of waterproofness difference.

The explanation of symbol

11 foamed sheets

12 bonding agents

13,14 fixture

15 notch.

Claims

1. a kind of adhesive tape has independent air bubble foamed sheet and the adhesive phase at least one face of the foamed sheet is arranged in,

The arithmetic average roughness Ra of at least one side of the foamed sheet is 1~12 μm,

The peel strength of described adhesive layer is 1.1N/25mm or more, with a thickness of 10 μm or more.

2. adhesive tape according to claim 1 is only provided with adhesive phase, the foamed sheet in the foamed sheet on one side Another side arithmetic average roughness Ra be 1~12 μm.

3. adhesive tape according to claim 1 or 2,50% compressive strength of the foamed sheet is 40~300kPa.

4. adhesive tape described in any one of claim 1 to 3, the interlaminar strength of the foamed sheet is 0.8~3.0MPa.

5. adhesive tape according to any one of claims 1 to 4, the foamed sheet with a thickness of 0.1~1.5mm.

6. adhesive tape according to any one of claims 1 to 5, the expansion ratio of the foamed sheet is 1.2~20cm³/g。

7. adhesive tape described according to claim 1~any one of 6, the mean air bubble diameter of the foamed sheet is 20~150 μ m。

8. adhesive tape according to any one of claims 1 to 7, the degree of cross linking of the foamed sheet is 25 mass % or more.

9. adhesive tape described according to claim 1~any one of 8, the foamed sheet contains polyolefin-based resins.

10. adhesive tape described according to claim 1~any one of 9, the foamed sheet contains 50 mass % of polyvinyl resin More than.

11. adhesive tape described according to claim 1~any one of 10, described adhesive layer with a thickness of 10 μm or more and 55 μm or less.